Transition From Substance-Induced Psychosis to Schizophrenia Spectrum Disorder or Bipolar Disorder

Problematic diagnosis of substance-induced disorders in ICD-11

The ICD-11 was introduced in January 2022. In chapter 6, "Mental, behavioral and neurodevelopmental disorders" we find the section "Disorders due to substance use and addictive behaviors" (section 6C4). Changes from the ICD-10 in this section include broadening the categories of harmful use and dependence, including more types of substances, and the addition of more behavioral addictions (gaming disorder). These changes have been discussed and debated [1].

Discussing the concept of substance-induced psychosis (SIP)

Substance-induced psychosis (SIP) is characterized by both substance use and a psychotic state, and it is assumed that the first causes the latter. In ICD-10 the diagnosis is categorized as and grouped together with substance use disorders, and to a large extent also treated as such in the health care system. Though criticism of the diagnostic construct of SIP dates back several decades, numerous large and high-quality studies have been published during the past 5-10 years that substantiate and amplify this critique. The way we understand SIP and even how we name it is of major importance for treatment and it has judicial consequences. It has been demonstrated that substance use alone is not sufficient to cause psychosis, and that other risk factors besides substance use are at play. These are risk factors that are also known to be associated with schizophrenia spectrum disorders. Furthermore, register-based studies from several different countries find that a large proportion, around one in four, of those who are initially diagnosed with an SIP over time are subsequently diagnosed with a schizophrenia spectrum disorder. This scoping review discusses the construct validity of SIP considering recent evidence. We challenge the immanent causal assumption in SIP, and advocate that the condition shares many features with the schizophrenia spectrum disorders. In conclusion, we argue that SIP just as well could be considered a first-episode psychotic disorder in patients with substance use.

The Resurgence of Exogenous Psychosis: A Phenomenological Examination of Substance-Induced Psychopathology

ABSTRACT

The psychopathological manifestations associated with substance use, including induced psychotic experiences, are increasingly relevant but not well-understood within the medical community. Novel psychoactive substances and potentiated old compounds like cannabis and cocaine have emerged as a global concern, especially among adolescents and young adults. Transition rates from substance-induced psychosis (SIP) to persistent psychosis are significant, particularly in cases of cannabis-induced psychosis. Scientific inquiry into induced psychotic phenomena has revealed differences between SIP and primary psychotic disorders, highlighting the risk factors associated with each. The concept of exogenous psychosis, including its toxic variant known as lysergic psychoma, provides valuable insights into the role of external factors in psychosis development. A phenomenological approach characterizes this disruption in perception as a shift in temporal and spatial dimensions, leading to auditory and visual hallucinations. The "twilight state" of consciousness plays a crucial role in the transition from substance use to psychosis, with implications for spatiality, intersubjectivity, and temporality. This complex path to psychosis challenges traditional diagnostic models and underscores the need for a more nuanced understanding of substance-induced psychopathological experiences.

Behind the heterogeneity in the long-term course of first-episode psychosis: Different psychotic symptom trajectories are associated with different patterns of cannabis and stimulant use

BACKGROUND

Data-driven classification of long-term psychotic symptom trajectories and identification of associated risk factors could assist treatment planning and improve long-term outcomes in psychosis. However, few studies have used this approach, and knowledge about underlying mechanisms is limited. Here, we identify long-term psychotic symptom trajectories and investigate the role of illness-concurrent cannabis and stimulant use.

METHODS

192 participants with first-episode psychosis were followed up after 10 years. Psychotic symptom trajectories were estimated using growth mixture modeling and tested for associations with baseline characteristics and cannabis and stimulant use during the follow-up (FU) period.

RESULTS

Four trajectories emerged: (1) Stable Psychotic Remission (54.2 %), (2) Delayed Psychotic Remission (15.6 %), (3) Psychotic Relapse (7.8 %), (4) Persistent Psychotic Symptoms (22.4 %). At baseline, all unfavorable trajectories (2-4) were characterized by more schizophrenia diagnoses, higher symptom severity, and longer duration of untreated psychosis. Compared to the Stable Psychotic Remission trajectory, unstable trajectories (2,3) showed distinct associations with cannabis/stimulant use during the FU-period, with dose-dependent effects for cannabis but not stimulants (Delayed Psychotic Remission: higher rates of frequent cannabis and stimulant use during the first 5 FU-years; Psychotic Relapse: higher rates of sporadic stimulant use throughout the entire FU-period). The Persistent Psychosis trajectory was less clearly linked to substance use during the FU-period.

CONCLUSIONS

The risk for an adverse long-term course could be mitigated by treatment of substance use, where particular attention should be devoted to preventing the use of stimulants while the use reduction of cannabis may already yield positive effects.

The Prediction of Diagnostic Change From Bipolar Disorder to Schizophrenia and Schizophrenia to Bipolar Disorder in a Population-Based, Longitudinal, National Swedish Sample

BACKGROUND AND HYPOTHESIS

To clarify, in a large, representative, longitudinal sample, the rate and predictors of diagnostic conversion from Bipolar Disorder (BD) to Schizophrenia (SZ) and from SZ→BD.

DESIGN

From individuals born in Sweden 1950-1995 and living there in 1970 or later, we identified at least one initial diagnoses of SZ (n = 8449) and BD (n = 8438) followed for a minimum of 10 and a mean of 24 years. Diagnostic conversion required, respectively, at least two final diagnoses of BD and SZ 30 days apart with no intervening diagnosis of SZ or BD.

RESULTS

At follow-up, rates of BD→SZ and SZ→BD conversion were 10.1 and 4.5%, respectively. Conversions occurred slowly, with around 50% completed in the first decade. Using a diverse range of variables available at first onset including family genetic risk scores, BD→SZ conversion was predicted with greater accuracy (AUC = 0.78) than SZ→BD conversion (AUC = 0.65). The strongest predictors of BD→SZ conversion were earlier years of birth, younger age at BD onset, low BD genetic risk, and being unmarried at BD onset. SZ→BD conversion was most strongly predicted by high BD genetic risk, being married at SZ onset, female sex, early age at SZ onset, and an MD episode prior to SZ onset. Cases of BD and SZ in the highest decile for conversion risk had HRs for a diagnostic change of, respectively, 12.5 and 3.4.

CONCLUSIONS

Diagnostic conversion of BD→SZ and SZ→BD are not rare, are moderately predictable, and should likely be accounted for in many research designs.

Rethinking Mental Automatism: De Clérambault's Theory in the Age of Novel Psychoactive Drugs: Psychotropic Effects and Synthetic Psychosis

The widespread use of novel psychoactive substances (NPSs)-defined as new narcotic or psychotropic agents not classified under the Single Convention on Narcotic Drugs of 1961 or the Convention on Psychotropic Substances of 1971-poses a significant challenge to contemporary mental health paradigms due to their impact on psychiatric disorders. This study revisits and expands upon the theory of mental automatism as proposed by Gaëtan Gatian de Clérambault, aiming to elucidate the psychopathological mechanisms underlying substance-induced psychoses (SIP) and their distinction from non-induced psychoses (schizophrenia and related disorders). Through a phenomenological and clinical investigation, we explore the relevance of mental automatism in the development of toxic psychoses, drawing upon the historical and contemporary literature. This research highlights the psychopathological distinctions between induced and non-induced psychoses and the transition mechanisms from acute to chronic psychosis states. De Clérambault's theory, supplemented by Janet, Jackson, and Bonhoeffer's contributions, provides a foundational framework for understanding the genesis of SIP. Our findings suggest that NPS consumption, particularly among adolescents and psychiatric patients, significantly correlates with increased risks of SIP, marked by a transition to chronicity influenced by biological lesions triggered by substance use. Furthermore, we propose a comprehensive framework for SIP, integrating mental automatism, psychopathological distinctions, and transition mechanisms. This framework aims to refine diagnostic criteria and therapeutic approaches, addressing gaps in clinical practice and research. The study underscores the need for a nuanced understanding of SIP, advocating for a paradigm shift in psychiatric assessment and treatment approaches to better address the complexities of substance-induced mental health disorders.

The predictive effect of family genetic risk scores as an indirect measure of causal effects of one disorder on another

BACKGROUND

One potential cause of comorbidity is the direct causal effect of one disorder - A - on risk for subsequent onset of disorder B. Could genetic risk scores be utilized to test for such an effect? If disorder A causally impacts on risk for disorder B, then genetic risk for disorder A should be lower in cases of disorder A with v. without a prior onset of B.

METHODS

In all individuals (n = 905 736) born in Sweden from 1980 to 1990, from six psychiatric and drug use disorders (major depression, anxiety disorders, alcohol use disorder, drug use disorder, bipolar disorder, and schizophrenia), we formed 14 pairs of disorders A and B. In these pairs, we compared, using Cox proportional hazards models, the predictive effect of the familial-genetic risk score (FGRS) for disorder B in those who had v. had not had a prior onset of disorder A.

RESULTS

In all pairs, the impact of the FGRS for disorder B was significantly stronger in cases without v. with a prior history of disorder A. These effects were similar across sex, stable across levels of FGRS and not likely due to clinician bias. In many of our disorder pairs, previous clinical studies suggest a mechanism for a causal effect of disorder A on B.

CONCLUSIONS

Our findings provide indirect evidence that the occurrence of one psychiatric or substance use disorder often has a causal effect on risk for subsequent disorders. This mechanism may substantially contribute to the widespread comorbidity among psychiatric conditions.

Impact of non-medical cannabis legalization with market restrictions on health service use and incident cases of psychotic disorder in Ontario, Canada

BACKGROUND

Cannabis is a risk factor in the onset and persistence of psychotic disorders. There is concern that non-medical cannabis legalization in Canada may have population-level impacts on psychotic disorders. We sought to examine changes in health service use and incident cases of psychotic disorder following cannabis legalization, during a period of tight restrictions on retail stores and product types.

METHODS

We conducted a cross-sectional interrupted time-series analysis using linked population-based health administrative data from Ontario (Canada) from January 2014 to March 2020. We identified psychosis-related outpatient visits, emergency department visits, hospitalizations, and inpatient length of stay, as well as incident cases of psychotic disorders, among people aged 14 to 60 years.

RESULTS

We did not find evidence of increases in health service use or incident cases of psychotic disorders over the short-term (17 month) period following cannabis legalization. However, we found clear increasing trends in health service use and incident cases of substance-induced psychotic disorders over the entire observation window (2014-2020).

CONCLUSION

Our findings suggest that the initial period of tight market restriction following legalization of non-medical cannabis was not associated with an increase in health service use or frequency of psychotic disorders. A longer post-legalization observation period, which includes expansion of the commercial cannabis market, is needed to fully understand the population-level impacts of non-medical cannabis legalization; thus, it would be premature to conclude that the legalization of non-medical cannabis did not lead to increases in health service use and incident cases of psychotic disorder.